You forgot to remove existing source tags in modules main, extensions/hadoop and extensions/java7. Remove those and I will merge.

hrm, didn't realize that you can't target bytecode older than than the source. Makes sense when I think about it. This now proposes targeting 1.8 in full (and requiring 1.8 JVM).
Its old enough that most projects would be okay with it (hopefully)

It is possible to use an older target with a newer source, but not the other way around.

There are still people using argparse4j on JDK 6, so we cannot upgrade to JDK 8: #63

We want to be able to set the target JDK per module (1.6 for the core, 1.7 for the Java 7 extension, etc.), but it is fine to set the sources JDK to 1.8 for all modules. Building with 1.8 is also not a problem, and I have a change in the queue that will check that classes from newer JDKs are not used on the CI server: #95

Because of #95 (which I assume will be merged soon) there is no need to specify the JDK in the Travis file.

I am sorry to see that you decided to revert your changes. The switch to Java 1.8 syntax is not a problem at all, but we must continue to support users that still deploy on Java 1.6. You can create another PR that only changes the source version to 1.8, or else I will make the changes myself soonish.

I plan on making the changes, this PR conflicted in ways that were difficult to recover.
That said, if you get to it first, it will still be cool.